Quantitative evaluation of the CEEM soil sampling intercomparison

Area of Science:

• Environmental Science
• Analytical Chemistry
• Soil Science

Background:

• Existing soil sampling and preparation guidelines vary significantly across European Union member states and Switzerland.
• These variations hinder comparable results in soil contamination investigations, monitoring, and risk assessments.

Purpose of the Study:

• To compare and evaluate soil sampling and sample preparation guidelines used in European countries.
• To identify factors causing incomparability in soil contamination studies.
• To provide recommendations for harmonizing European soil sampling guidelines.

Main Methods:

• Established a reference database (RDB) for quantitative comparison of participant results.
• Compared participant samples (centrally and individually analyzed) against the RDB and soil quality standards for metals (cadmium, copper, lead, zinc).
• Calculated deviations, categorized comparability, applied statistical analysis for method bias, and compiled methodological profiles.

Main Results:

• Significant deviations were observed in results due to methodological differences in sampling strategies.
• Comparability of samples with the RDB was categorized into four levels, highlighting method-specific errors.
• Identified specific strategies and methods that are problematic for achieving comparable results.

Conclusions:

• Current diverse soil sampling and preparation methods lead to incomparable results in contamination studies.
• Standardization and specification of methods are necessary for representative and comparable European soil data.
• Pre-normative recommendations for harmonizing guidelines and standard operating procedures are essential.